<template>
    <div class="xtx-carousel" @mouseenter="stop()" @mouseleave="start()">
        <ul class="carousel-body">
            <li class="carousel-item" :class="{fade:index === i}" v-for="(item,i) in sliders" :key="i">
                <RouterLink v-if="item.imgUrl" to="/">
                    <img :src="item.imgUrl" alt="" />
                </RouterLink>
                <div v-else class="slider">
                    <RouterLink v-for="goods in item" :key="goods.id" :to="`/product/${goods.id}`">
                        <img :src="goods.picture" alt="">
                        <p class="name ellipsis">{{goods.name}}</p>
                        <p class="price">&yen;{{goods.price}}</p>
                    </RouterLink>
                </div>
            </li>
        </ul>
        <a @click="toggle(-1)" href="javascript:;" class="carousel-btn prev"><i class="iconfont icon-angle-left"></i></a>
        <a @click="toggle(1)" href="javascript:;" class="carousel-btn next"><i class="iconfont icon-angle-right"></i></a>
        <div class="carousel-indicator">
            <span @click="index = i" v-for="(item,i) in sliders" :key="i" :class="{active:index === i}"></span>
        </div>
    </div>
</template>

<script>
import { ref, watch } from "vue";
export default {
    name: "XtxCarousel",
    props:{
        sliders:{
            type:Array,
            default:()=>[]
        },
        // 是否自动轮播
        autoPlay:{
            type:Boolean,
            default:false
        },
        // 间隔时长
        duration:{
            type:Number,
            default:3000
        }
    },
    setup(props){
        // 控制显示图片的索引
        const index = ref(0)
        
        // 自动轮播
        let timer = null;
        const autpPlayFn = ()=>{
            // 防止定时器重复添加
            clearInterval(timer)
            timer = setInterval(() => {
                index.value++;
                if (index.value>=props.sliders.length) {
                    index.value = 0;
                }
            }, props.duration);
        }
        // 需要监听 sliders数据变化，判断如果有数据且autoPlay为true
        watch(()=>props.sliders ,(newVal)=>{
            if (newVal.length>0 && props.autoPlay) {
                autpPlayFn()
            }
        },{ immediate:true })

        // 如果正在自动播放 鼠标进入 暂停轮播 离开 开启
        const stop = () =>{
            if (timer) {
                clearInterval(timer)
            }
        }
        const start =() =>{
            if (props.sliders.length&&props.autoPlay) {
                autpPlayFn()
            }
        }
        // 点击上一张 下一张
        const toggle =(step) =>{
            // 将要改变的索引
            const newIndex = index.value+step;
            if (newIndex>props.sliders.length - 1) {
                index.value = 0
                return
            }
            if (newIndex < 0) {
                index.value = props.sliders.length - 1;
                return
            }
            // 正常
            index.value = newIndex
        }
        return {
            index,
            stop,
            start,
            toggle
        }
    }
};
</script>
<style scoped lang="less">
.xtx-carousel {
    width: 100%;
    height: 100%;
    min-width: 300px;
    min-height: 150px;
    position: relative;
    .carousel {
        &-body {
            width: 100%;
            height: 100%;
        }
        &-item {
            width: 100%;
            height: 100%;
            position: absolute;
            left: 0;
            top: 0;
            opacity: 0;
            transition: opacity 0.5s linear;
            &.fade {
                opacity: 1;
                z-index: 1;
            }
            img {
                width: 100%;
                height: 100%;
            }
        }
        &-indicator {
            position: absolute;
            left: 0;
            bottom: 20px;
            z-index: 2;
            width: 100%;
            text-align: center;
            span {
                display: inline-block;
                width: 12px;
                height: 12px;
                background: rgba(0, 0, 0, 0.2);
                border-radius: 50%;
                cursor: pointer;
                ~ span {
                    margin-left: 12px;
                }
                &.active {
                    background: #fff;
                }
            }
        }
        &-btn {
            width: 44px;
            height: 44px;
            background: rgba(0, 0, 0, 0.2);
            color: #fff;
            border-radius: 50%;
            position: absolute;
            top: 228px;
            z-index: 2;
            text-align: center;
            line-height: 44px;
            opacity: 0;
            transition: all 0.5s;
            &.prev {
                left: 20px;
            }
            &.next {
                right: 20px;
            }
        }
    }
    &:hover {
        .carousel-btn {
            opacity: 1;
        }
    }
}
// 轮播商品
.slider {
    display: flex;
    justify-content: space-around;
    padding: 0 40px;
    > a {
        width: 240px;
        text-align: center;
        img {
            padding: 20px;
            width: 230px!important;
            height: 230px!important;
        }
        .name {
            font-size: 16px;
            color: #666;
            padding: 0 40px;
        }
        .price {
            font-size: 16px;
            color: @priceColor;
            margin-top: 15px;
        }
    }
}
</style>